University College London Hospitals (UCLH) in the UK has initiated dosing in two clinical trials of a long-acting antibody (LAAB) combination therapy to provide protection against Covid-19.

AstraZeneca’s LAAB or AZD7442 is a combination of monoclonal antibodies obtained from Covid-19 convalescent patients.

The STORM CHASER study led by UCLH virologist Dr Catherine Houlihan enrolled 10 participants so far.

Researchers believe that AZD7442 could provide immediate and long-term protection to individuals recently exposed to the SARS-CoV-2, to prevent them from developing Covid-19.

Dr Houlihan said: “We know that this antibody combination can neutralise the virus, so we hope to find that giving this treatment via injection can lead to immediate protection against the development of Covid-19 in people who have been exposed – when it would be too late to offer a vaccine.”

Another study, PROVENT, is analysing the use of AZD7442 in individuals who may not respond to vaccination (people with a compromised immune system) or those who are at high risk of Covid-19 infection, owing to factors like age and existing conditions.

UCLH portion of PROVENT is led by UCLH infectious diseases consultant Dr Nicky Longley, who said: “We will be recruiting people who are older or in long-term care, and who have conditions such as cancer and HIV, which may affect the ability of their immune system to respond to a vaccine.

“We want to reassure anyone for whom a vaccine may not work that we can offer an alternative which is just as protective.”

In both the trials, researchers will evaluate whether the therapy lowers the risk of developing Covid-19 and/or lowers the severity of the disease versus placebo.

PROVENT and STORM CHASER studies are being carried out at the newly opened Vaccine Research Centre at UCLH.

In August, AstraZeneca started dosing participants in a Phase I clinical trial of monoclonal antibody combination therapeutic AZD7442 to prevent and treat Covid-19.